Monte-Carlo simulations analyze the photon collection in photovoltaic systems with fluorescent collectors. We compare two collector geometries: the classical setup with solar cells mounted at each collector side and solar cells covering the collector back surface. For small ratios of collector length and thickness, the collection probability of photons is equally high in systems with solar cells mounted on the sides or at the bottom of the collector. We apply a photonic band stop filter acting as an energy selective filter which prevents photons emitted by the dye from leaving the collector. We find that the application of such a filter allows covering only 1% of the collector side or bottom area with solar cells. Furthermore, we compare ideal systems in their radiative limits to systems with included loss mechanisms in the dye, at the mirror, or the photonic filter. Examining loss mechanisms in photovoltaic systems with fluorescent collectors enables us to estimate quality limitations of the used materials and components.

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We present a photovoltaic triple junction system made of two stacked fluorescent collector plates and gallium-indiumarsenide (GaInP), gallium-arsenide (GaAs) and silicon (Si) solar cells, utilizing the spectral selectivity of fluorescent conversion. Fluorescent collectors use fluorescent dye molecules embedded in a dielectric material to collect solar radiation. Incoming radiation is converted into radiation of lower energy, reduced by the Stokes shift energy ∆E. Total internal reflection keeps part of the converted radiation inside the collectors and guides it to the edges of the collector plates, where GaInP and GaAs solar cells are mounted. In order to make use of the spectral selectivity of each collector, the band gap energies E g of the solar cells at the edges match the energy of dye emission. Optical transmission, reflection and photoluminescence measurements analyze the fluorescent collectors. A spectral transfer matrix formalism allows us to calculate the emitted photon flux of each collector as a function of the absorption/emission properties of the dye and the spectrum of incident radiation. By multiplying the transfer matrices tailored on each collector with the quantum efficiencies of the solar cells, we obtain the particular quantum efficiencies of each collector-cell sub-system and the overall quantum efficiency of the triple junction system. The results show very good agreement in the shape of predicted and measured quantum efficiency curves of the triple junction system.